But what would happen if we tried to grow great redwoods on Mars. I think it would be incredibly difficult. We think that the trees are large now, but they could very well grow up into the little atmosphere Mars has. We could say, then, that the trees would be 62% larger than they are here on Earth. I doubt this is true, but for arguments sake, it is plausible.
There is no way the trees would be able to survive such a drastic change in size. The trees would snap because the fibers of the tree will have been stretched beyond anything on Earth could have done. We would require decades of cultivation, just to grow a sustainable trees. Very much like how Cannabis cultivation over the past 20 or so years has yielded higher and higher THC levels because of cultivation.
How can we get around the problem of less tensile strength in the tree fibers so that we may skip the decades of cultivation, just to find, and possibly even "create" trees that are sustainable on Mars?
Look to the oceans :-). Plants have learned to live in environments where changes in gravity have played a key role how the plant grew and evolved over time. I can imagine on Mars, buildings whose sole purpose is to house algae. Rows upon rows upon rows of algae, feeding on carbon dioxide. The change in gravity may affect the algae, but not anywhere near how it would affect traditional plants such as trees or flowers.
So, NASA, send me to Mars. I want to help.